Crystal bending tool

ABSTRACT

THIS DISCLOSURE IS DIRECTED TO A MECHANICAL DEVICE OR TOOL FOR BENDING CRYSTALS ON A KNOWN RADIUS WITHOUT ANY DELETREIOUS EFFECTS ON THE CRYSTAL. ONE ADJUSTABLE ROLLER IS MOVED ON AN ARC RELATIVE TO A FIXED CYLINDER SO THAT THE ROLLER MAINTAINS A DESIRED RADIUS WITH RESPECT TO THE FIXED CYLINDER TO FORM A CURVED CRYSTAL HAVING A SPECIFIC THICKNESS AND CURVATURE.

Oct. 12, 1971 RS 3,611,776

CRYSTAL BENDING TOOL Filed Oct. 22, 1969 lg\ l7 I H L i] U] INVENTUR 25 '1 RICHARD L. SAUNDERS 22 BY VXGENT M/ I ATTORNEY United States Patent O 3,611,776 CRYSTAL BENDIN G TOOL Richard L. Saunders, Fort Washington Forest, Md., as-

signor to the United States of America as represented by the Secretary of the Navy Filed Oct. 22, 1969, Ser. No. 868,536

Int. Cl. B21d 7/02 US. Cl. 72219 4 Claims ABSTRACT OF THE DISCLOSURE This disclosure is directed to a mechanical device or tool for bending crystals on a known radius without any deleterious effects on the crystal. One adjustable roller is moved on an arc relative to a fixed cylinder so that the roller maintains a desired radius with respect to the fixed cylinder to form a curved crystal having a specific thick ness and curvature.

STATEMENT OF GOVERNMENT INTEREST The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

BACKGROUND OF THE INVENTION Heretofore, a Pat. No. 2,835,820 was issued for a curved crystal spectrograph. The spectrograph required a crystal with a uniform curvature. Therefore, there was a need to produce accurately curved crystals. The crystals used were curved by less sophisticated methods and the process was uncertain such that the rejection rate was about 60- 70%. Similar devices have been used for bending tubes or pipe in the electrical and plumbing field. Such devices have been found to be too crude to produce suitable curved crystals with accuracy. Also, some of the crystals used are very thin and known pipe bending devices break more crystals than are made useful as pointed out above.

The device of the present invention makes use of three relatively movable parts each cooperating together in such a manner that crystals may be curved without damage to the crystals. The crystal is formed around a cylindrical element by the use of an adjustable roller which is adjusted to a set clearance from the fixed cylindrical member and the roller is then moved about the fixed cylinder by the third element. The crystal is fixed in place relative to the fixed cylinder and then the entire device is hung in a heated oven to soften the crystal. The device is removed from the oven and the crystal is curved while in a softened state. The crystal is removed from the device as soon as possible after being curved.

STATEMENT OF THE OBJECTS It is therefore an object of the present invention to provide a mechanical device which is suitable for curving crystals without any deleterious effects on the crystals.

Another object is to provide a simple device for curving crystals that may be operated by an unskilled as well as a skilled operator.

Another object is to provide a crystal curving device which may be adjusted for crystals having different thickness.

Still another object is to provide a device for curving a crystal without handling the crystal while curving the crystal.

Other objects and advantages of the invention will be obvious to those skilled in the art upon consideration of the following drawing and specification.

3,611,776 Patented Oct. 12, 1971 ice BRIEF DESCRIPTION OF THE DRAWINGS DESCRIPTION OF THE DRAWINGS Now referring to the drawing, there is shown by illustration a crystal bending device made in accordance with the teaching of this invention. As shown, the device includes three main elements 11-13 which are movable relative to each other. Element 12 is rotatably secured relative to element 11 and element 13 is secured onto element 12 and movable relative thereto such as a scissors movement. Element 11 is made with an arm extension 14 and a cylindrical end 15. The cylindrical end is formed such that the curvature of the cylindrical end meets with the upper surface of the arm extension on a tangent at the point that a radial line 16 (shown in dotted line) is perpendicular to the arm surface. The elements 14 and 15 may be milled from a single piece of metal or they may be separate pieces, properly formed and secured together.

Element 12 is formed from a single piece of metal which is slightly wider than element 11 so that bifurcated ends 17 slide over the cylindrical end with a close fit. The bifurcated ends are secured to cylindrical end 15 on its axis by a suitable bolt 18 or pin that may extend through the cylindrical element or screw into the surface thereof such that the element 12 is free to move about the axis of the cylindrical element 15. The element 12 is provided with a cut out 19 outwardly of the bifurcated ends through which element 13 extends and is secured thereto by a suitable bolt 21 or any other suitable means such that the element 13 is free to move about the bolt relative to element 12.

The element 13 may be curved such that the end 22 near the cylindrical end 15 is curved downwardly toward the end 15 and the outer end 23 is curved toward the element 12. The lower end 22 of element 13 is wider than the main section and is substantially as wide as the width of element 11. The end 22 of element 13 is bifurcated to include ends 24 between which a cylindrical roller 25 is secured by suitable pins or a bolt coaxial therewith. The assembly of the bifurcated ends 24 and the roller is such that a close clearance is made with the inner surfaces of the bifurcated ends 17 of element 12 within which the element 13 must move relative thereto.

The outer end 23 of the element 13 is curved such that the end is substantially parallel with the upper surface of element 12 and spaced therefrom when the curved end 22 is in close proximity to the lower surface of element 12. The length of element 13 between the pivot point and the cylindrical end 15 of element 11 is such that the roller has a slight clearance between the roller and the cylindrical end when the end 22 of element 13 has been moved its maximum permissible distance toward the lower side of the element 12 and the curved end 23 has been moved its maximum distance toward the upper surface of element 12. The relationship of the roller 25 with respect to the cylindrical end 15 and the pivot point of the bifurcated ends 17 of element 12 is such that the roller moves in an are about the cylindrical end which is a constant distance from the circumference of the cylindrical element as the element 12 is moved about the cylindrical end on its pivot. Thus, the roller follows a path which has the same curvature as the curvature of the surface of the cylindrical end member and is a constant distance from the circumference of the cylindrical end. v

This device is useful in curving crystals of different thickness, therefore, the device is provided with means for adjusting element 13 relative to element 12. As shown,

an adjusting bolt 26 is threaded through the element 12 and the length on each side is adjusted by rotation of the bolt within the threaded aperture in element 12. Lock nut 27 is provided for threading against element 12 to prevent the bolt from movement once it has been properly set. The end 23 of element 13 is curved toward element 12 such that the end 23 is substantially parallel with the surface of element 12, therefore, the adjusting bolt limits the movement of element 13 toward element 12; that is, end 23 rests upon the bolt to limit its movement toward the element 12. Since end 23 of element 13 is limited in its movement toward element 12, the roller end 22 is limited in movement and therefore is set at a specific distance from the surface of cylindrical end 15.

Since the idea of the device is to curve a crystal 33 to a specific curvature there is provided a crystal holding means on element 11. The crystal holding means shown is a rectangular plate 31 held in place by two screws 32. The end of the holder which holds the crystal is positioned such that the edge of the plate is in alignment with the line of tangency between the arm end 14 of element 11 and the cylindrical end 15. Arm end 14 of element 11 is provided with a standoff screw or bolt 28 which is locked by nut 29. The standoff bolt in arm 14 is used to aid in the adjustment of the roller with respect to the cylindrical end 15 in ordler to curve the crystal without breakage of the crystal.

In carrying out the application of the crystal bending device, the device is used as follows; that is, assuming that the parts have been assembled into an operative device. The elements 11 and 12 are moved toward each other such that the roller end of element 13 is above the crystal holder. With the roller end of element 13 away from the crystal holder, the crystal is set in place with one end under the holder plate and the free end extending outwardly from the holder such as shown in FIG. 1. While holding element 12 stationary, element 13 is moved toward element 11 until the surface of element 13 rests against standoff bolt 28. While holding element 13 against the standoff bolt, element 12 is moved toward elements 11 and 13. In order to insure that the roller end of element 13 does not hit the crystal and break the crystal during movement of element 12 toward elements 11 and 13, the adjusting bolt 28 is threaded toward element 13 sulficiently such that when element 12 is moved until the adjusting bolt rests upon the lower surface of element 13, the roller will not touch the crystal. It is seen that as element 12 is moved toward elements 13 and 11 that the roller end of element 13 moves toward the crystal. Therefore, with element 13 positioned against standoff bolt 28 and with the adjusting screw 26 against element 13 on the opposite surface, the adjusting screw is backed off permitting the roller end of element 13 to move closer to the crystal. Once the adjusting screw has been properly adjusted such that the roller is properly set, the lock nut 27 is tightened to lock the adjusting screw in place.

The crystal bending device is now properly set with the crystal in place. The device is then hung in an oven such that the arms are forced toward each other to insure that the roller does not contact and break the crystal. Once the crystal has been heated sufiiciently to freely bend the crystal around the circumference of the cylindrical end, the device is removed from the oven. Now the ele ment 13 is held against the adjusting screw 26 so that the roller is in contact with the crystal and the element 12 is moved around the cylindrical end. As the element 12 is moved around the cylindrical end with element 13 held in place against the adjusting screw, the roller end presses against the crystal forcing the crystal around the cylindrical end. Therefore, the crystal takes the same curvature as the cylindrical end of element 11. The crystal is 4 removed from the bending tool as quickly as possible after removing from the furnace.

The crystal bending device of this invention permits one to curve crystals without having to handle the crystal during the process of curving the crystal and especially while it is hot.

Of course, one skilled in the art would realize that the device must be handled with protective gloves, once it has been heated to prevent a burn damage to the hands.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that the invention may be practiced otherwise than as specifically described.

What is claimed and desired to be secured by Letters Patent of the United States:

1. A crystal bending device which comprises:

first, second, and third elements operatively assembled together,

said first element including an arm extension and a cylindrical end integral therewith,

said second element including an arm extension with a bifurcated end with said bifurcated end secured to said cylindrical end of said first element on the axis thereof and rotatable relative thereto about said cylindrical end,

said third element secured to said second element for a scissors-like movement relative thereto with movement of said third element in the plane of rotational movement of said second element relative to said cylindrical end such that one end of said third element is directed toward said cylindrical end,

a roller on the end of said third element directed toward said cylindrical end in spaced relationship therewith with the axis of said roller parallel with the axis of said cylindrical end,

an adjusting means on said second element for adjusting the position of said roller in a radial direction relative to said cylindrical end, and

means secured onto said first element relative to said cylindrical end for holding a crystal in place relative to said cylindrical end for bending of said crystal about the circumference of said cylindrical end.

2. A crystal bending device as claimed in claim 1; wherein:

said second element includes a cutout outwardly of said bifurcated end, and

said third element is mounted within said cutout within said second element for pivotal movement relative thereto.

3. A crystal bending device as claimed in claim 2;

wherein:

said crystal holding means is secured onto said first element such that the edge of the holding means is on the tangent line where the outer surface of the cylindrical end meets the arm extension.

4. A crystal bending device as claimed in claim 3;

wherein:

said third element is of a somewhat S-shape with the outer and inner ends directed toward said second element.

References Cited UNITED STATES PATENTS 1,824,026 9/1931 Little 72219 X 627,162 6/1899 Wallace 72217 1,688,199 10/1928 Meier 72217 X 3,126,773 3/1964 Taylor, Jr., et a1. 72409 X MILTON S. MEHR, Primary Examiner 

